It would be useful to have a hook to allow a plugin to install functions to be run at the points covered by special aliases - UNKNOWN_CMD, PRE_EXEC, POST_EXEC and PRE_INPUT. They would allow plugins to trap these cases without having to interfere with the aliases (which is error-prone, as it's not obvious how to "chain" the plugin hook with a user-set alias). One use-case I have is for a timing plugin, which sets pre- and post-exec hooks, to display the time taken by the last command. (This is possible at the moment with aliases, but as I say, it's more fiddly than it would be in a plugin). As a suggestion for the interface, how about special names, *PRE_INPUT etc (which fit in the keyboard hook namespace, but I doubt the names will clash with existing names used by plugins). Only *UNKNOWN_CMD requires any input (the command line), which could be made available via the normal NthArgument etc API calls. Paul.